The Forest Republican. [volume] (Tionesta, Pa.) 1869-1952, 1887-03-30
SCIENTIFIC AND INDUSTRIAL.


Take care how you let any machine
oil or lubricator come in contact with
cut or scratch on your hand or arm, as
serious blood poisoning may result. In
the manufacture Of some of these ma
chine oils fat from diseased and decom-
posed animals is used. All physicians
know how poisonous such matter is.
The only safeguard is not to let any spot
where the skin is broken be touched by
any machine oil or lubricator
The recent exhaustive researches by
Mr.. Verbeek into all the phenomena con
nected with the red sun glows of 1sS:
and 1894 have led him to conclude that
they we're caused mainly by the masses
of aqueous vapor thrown out by the vol
cano Krakatoa. In this view, the watery
vapor elected by Krakatoa, after con
densing and freezing in the high air,
produces the remarkable sunset, though
the ashes may have intensified the pho
nomena besides serving as a centre of
condensation.
BY observing how far the sun has to
sink beneath the horizon before the top
most summit of the air is cut of from its
rays, Monsieur Bravais, some years ago,
determined the greatest upward limit of
twilight to be 37S, 900 feet, or nearly
seventy one miles above sea level BY
observing the earth's shadow on the
moon during eclipses, astronomers had
inferred that the atmosphere must be
sufficiently dense to produce twilight
for at least 240, 600 feet away from the
carth's surface.
Amember of the London Astronomi-
cal Society has pointed out that the COM
mon assumption that a fragment of me-
teor dust no larger than a mustard seed
may give the briliiancy of a first magni-
tude star, is erroneous. To give that
brightness at a distance of 100 miles,
about that at which meteors are usually
seen, would require an electric lamp of
10, 600 candle power 1t is therefore
probable that the smallest visible me
teors have a surface equal to the incan-
descent portion of a 100-candle power
electric arc, if not much greater.
The crop-destroying rabbit appears to
be not the only animal plague in Aus
tralia. The decay of the forests is traced
by Rev. P. Macpherson, of the Royal
Society of New South Wales, to the
opossums. After much investigation, it
was ascertained that a single animal
would devour about 800 leaves of the
Eucalyptus, or blue gum tres, in a night ;
proving that the $4,000 opossums
killed annually in the county of Victoria
were sufficient to destroy upwards of 49,.
600 trees and lay bare space of 700
acres, or more than a square mile.
MIR. ]. w. Walker reports some valu.
able archaeological discoveries upon the
south side of Pine Mountain, Georgia.
Upon the sides of the mountain, some
200 feet above the famous Corundum
Mine, he finds evidences of the site where
the ancient inhabitants of that section
fashioned their cooking utensils. Many
of these utensils are but half finished,
and are yet in place upon the bluff. This
'findH is very instructive, as it is anoth-
er proof of the manner in which these
vessels were formed. Stone implements
were used largely in this work, the YES
sci being nearly completed before final
detachment from the rock
Prof. J. S. Newberry gives a most
marked illustration of what appears to
be development Of instinct approaching
reason in one of the low forms of life.
The grub of the seventeen-year locust
buries itself deep in the ground, and
only emerges after its period of seven
teen years is ended. At Rahway, N. j.,
house has been erected above a spot
where some of these grabs had buried
themselves. At the expiration of their
period the grubs started on their way to
the surface, but emerged into the cellar,
where they were yet in the dark. In
order to reach the light they commenced
building small structures, and when first
noticed the floor Of the cellar was found
covered with small cones, some of them
more than six inches high, which these
cicadas had built in their exertions tc
traverse the dark cavity to the light
above ground.